In recent years, a copy-machine system has been built in which (i) a multifunction printer (MFP) having a combination of two or more functions such as a print function, a copy function, a scanning function, and a facsimile function and (ii) a control terminal (sever PC) are linked with each other via a network so that the MFP is controlled. Further, some MFPs are provided with a function of limiting users to specific MFP functions.
Disclosed in connection with such a limitation imposed on users is a technique of limiting users' operation by using a server PC to analyze authentication data extracted from a document. For example, Patent Document 1 (Japanese Unexamined Patent Application Publication No. 509751/2003 (Tokuhyo 2003-509751; published on Mar. 11, 2003)) discloses a method of verifying the authenticity of a document by making a comparison between (i) an identifying feature/seal read out by scanning the document and (ii) information stored in a database. Further, for example, Patent Document 2 (Japanese Unexamined Patent Application Publication No. 14591/2005 (Tokukai 2005-14591; published on Jan. 20, 2005) discloses a system in which a printer receives print data containing user information, sends the user information to a printer control terminal together with an authentication request, and carries out printing in accordance with the print data upon receiving authentication notification from the printer control terminal.